Antibody responses in human gnathostomiasis.

Sera from 4 patients with parasitologically confirmed gnathostomiasis and from 18 healthy individuals were studied by SDS-PAGE and Western blot analysis using radioiodinated protein A to detect antibody responses against crude aqueous somatic extract of advanced third stage larvae of Gnathostoma spinigerum (L3G). It was found that the L3G extract was highly complex, comprising of more than 40 polypeptides among which more than 20 components were antigenic in human. The relative M.W. of the proteins ranged from 13 kd to 150 kd with the major antigenic bands at 150, 135, 120, 94, 84, 82, 72, 55, 54, 49, 43, 38, 35, 32 and 28 kd. All 4 sera from gnathostomiasis patients gave almost an identical pattern of reactivities against the L3G antigens whereas sera from the normal individuals gave much lower reactivities against the L3G antigen of M.W. 38 kd and, in certain individuals, those of 49 and 43 kd. The present findings suggest that the serum antibody response against the parasite is specific and may be useful in a specific or a confirmed immunodiagnosis of human gnathostomiasis.

Electron microscopy of the advanced third-stage larvae of Gnathostoma spinigerum.

The morphological structures of the advanced third-stage larvae of Gnathostoma spinigerum are reported by using the scanning electron microscope. On the head-bulb, the larva bears two lateral lips, two labial papillae on each lip with an amphid between them. The head-bulb bears four transverse row of well-developed single-pointed hooklets. The number of the hooklets in each row increases posteriorly. The appearance of the hooklets by dorsal view and lateral view is also described. The whole body cuticle is transversely striated and covered with transverse rows of single-pointed spines which are dense on the anterior third of the body and became gradually less both in number and size towards the posterior extremity. The average number of transverse rows of these cuticular striations is 234. A pair of cervical papillae and an excretory pore are located on the anterior third of the body. A pair of body papillae is seen on the posterior half of the body. The subterminal anus is seen in the posterior extremity.